Aluminum-containing photonic crystal preparation method and product thereof

Abstract

The invention relates to a preparation method of an aluminum-containing photonic crystal and a product thereof. The method comprises the following steps: (a) carrying out first pretreatment on an aluminum-containing object; (b) performing first anodic treatment on the aluminum-containing object to generate N layers of sequentially stacked first aluminum oxide films on the surface of the aluminum-containing object; and (c) subjecting the aluminum-containing article to a second anodic treatment to create a second aluminum oxide film between the first aluminum oxide film and the aluminum-containing article. When the first anodizing treatment is carried out, periodic current signals are provided for the aluminum-containing object for N times; when the second anodizing treatment is carried out, a current signal which sequentially comprises the first preset time and the second preset time is provided for the aluminum-containing object. The first preset time is a slowly-increasing current signal which slowly increases from 0 to a preset current value, the second preset time is a constant current signal with the preset current value, and the preset current value is greater than the maximum current value of each periodic current signal during the first anodizing treatment. The second anodic treatment can adjust the light reflected by the external light source advancing to the second aluminum oxide film so as to improve the saturation and brightness of the color presented by the product.

Description

Technical Field

[0001] The present invention relates to a method for preparing an aluminum-containing photonic crystal, and particularly to a method for preparing an aluminum-containing photonic crystal and its products that can enhance color saturation and brightness. Background Art

[0002] Since photonic crystals were proposed by two scholars, S. John and E. Yablonovitch, in 1987, they have been successively applied in various technical fields. Compared with traditional chemical coloring techniques, the technique of using photonic crystals for color regulation has the characteristics of simple process, environmental protection and no pollution, and has thus been widely respected by the industry in the past decade.

[0003] For example, Chinese Patent Publication No. CN103243368A (hereinafter referred to as the previous case 1) discloses a method for preparing a two-dimensional photonic crystal structure for full-spectrum color regulation. The preparation method of the previous case 1 sequentially includes: (1) cleaning an aluminum sheet; (2) subjecting the aluminum sheet to an electrochemical polishing; (3) subjecting the aluminum sheet to an anodic oxidation with a 0.3M oxalic acid solution at a voltage of 50V for 12 hours to generate a first aluminum oxide film on the surface of the aluminum sheet; (4) subjecting the aluminum oxide film on the surface of the aluminum sheet to a wet etching with an etchant mixed with chromic acid and phosphoric acid for 12 hours; (5) subjecting the aluminum sheet to an anodic oxidation with the oxalic acid solution for 48 seconds to form a second aluminum oxide film on the first aluminum oxide film; (6) subjecting the second aluminum oxide film to a wet etching with the etchant for a time between 0.3 and 1.5 hours; (7) repeating the foregoing (5) and (6) 5 times; and (8) preparing a high-reflection coating on the aluminum sheet after (7) by magnetron sputtering.

[0004] Although the preparation method of the previous case 1 can regulate colors, however, the previous case 1 still needs to complete color display through the magnetron sputtering method of the foregoing (8), and the color saturation and brightness of the displayed colors are also quite limited. In addition, the previous case 1 also needs to repeatedly perform wet etching and anodic treatment, and its process is also relatively cumbersome.

[0005] From the above description, it can be seen that improving the color saturation and brightness of the products obtained by the photonic crystal preparation method is an important topic that those skilled in this technical field need to break through. Summary of the Invention

[0006] The first object of the present invention is to provide a method for preparing an aluminum-containing photonic crystal that can enhance color saturation and brightness.

[0007] Method for preparing aluminum-containing photonic crystal, comprising the following steps: step (a), step (b), and step (c). In step (a), a first pretreatment is performed on the aluminum-containing object to remove contaminants on the surface of the aluminum-containing object. In step (b), a first anodization is performed on the aluminum-containing object after step (a), so as to generate N first aluminum oxide films stacked in sequence in a first direction on the surface of the aluminum-containing object. The first direction refers to the direction from the first aluminum oxide film towards the aluminum-containing object. Each of the first aluminum oxide films has a plurality of first nanopore structures extending in the first direction and spaced apart from each other in a second direction substantially perpendicular to the first direction. In step (c), a second anodization is performed on the aluminum-containing object after step (b), so as to generate a second aluminum oxide film between the Nth first aluminum oxide film in the first aluminum oxide films and the surface of the aluminum-containing object. The second aluminum oxide film has a plurality of second nanopore structures extending in the first direction and spaced apart in the second direction. In the present invention, when performing the first anodization in step (b), an N-time periodic current signal is provided to the aluminum-containing object. In addition, when performing the second anodization in step (c), a current signal is provided to the aluminum-containing object. The current signal sequentially includes a first predetermined time and a second predetermined time. In the first predetermined time of step (c), a slowly increasing current signal that slowly increases from 0 to a predetermined current value is provided to the aluminum-containing object, and the predetermined current value of the slowly increasing current signal is greater than the maximum current value of each periodic current signal. In the second predetermined time of step (c), a constant current signal with the predetermined current value is provided to the aluminum-containing object.

[0008] In the method for preparing aluminum-containing photonic crystal according to the present invention, in step (c), the increasing rate of the slowly increasing current signal is to increase the current density value from 0 mA / cm 2 to 40 mA / cm 2 .

[0009] The method for preparing an aluminum-containing photonic crystal according to the present invention, in the first anodization treatment of step (b), the aluminum-containing object is immersed in a first electrolyte for implementation. In the second anodization treatment of step (c), the aluminum-containing object after step (b) is immersed in a second electrolyte different from the first electrolyte for implementation, and step (c) includes the following sub-steps: sub-step (c1) and sub-step (c2). In sub-step (c1), the aluminum-containing object after step (b) is completely immersed in the second electrolyte for a first reaction time of the second anodization treatment to form the second aluminum oxide film on the surface of the aluminum-containing object, and the first reaction time is greater than the first predetermined time of the current signal. In sub-step (c2), a first part of the aluminum-containing object after sub-step (c1) is removed from the second electrolyte, and the remaining part of the aluminum-containing object excluding the first part continues to be immersed in the second electrolyte for a second reaction time of the second anodization treatment to continuously form and thicken the second aluminum oxide film immersed in the second electrolyte on the surface of the aluminum-containing object.

[0010] The method for preparing an aluminum-containing photonic crystal according to the present invention further includes the following sub-steps in the second anodization treatment of step (c): sub-step (c3), sub-step (c4), and sub-step (c5). In sub-step (c3), a second part of the aluminum-containing object after sub-step (c2) is removed from the second electrolyte, and the remaining part of the aluminum-containing object excluding the first part and the second part continues to be immersed in the second electrolyte for a third reaction time of the second anodization treatment to continuously form and thicken the second aluminum oxide film immersed in the second electrolyte on the surface of the aluminum-containing object. In sub-step (c4), a third part of the aluminum-containing object after sub-step (c3) is removed from the second electrolyte, and the remaining part of the aluminum-containing object excluding the first part, the second part, and the third part continues to be immersed in the second electrolyte for a fourth reaction time of the second anodization treatment to continuously form and thicken the second aluminum oxide film immersed in the second electrolyte on the surface of the aluminum-containing object. In sub-step (c5), a fourth part of the aluminum-containing object after sub-step (c4) is removed from the second electrolyte, and the remaining part of the aluminum-containing object excluding the first part, the second part, the third part, and the fourth part continues to be immersed in the second electrolyte for a fifth reaction time of the second anodization treatment to continuously form and thicken the second aluminum oxide film immersed in the second electrolyte on the surface of the aluminum-containing object.

[0011] The method for preparing an aluminum-containing photonic crystal according to the present invention, in the first anodization treatment of step (b), the aluminum-containing object is immersed in a first electrolyte for implementation. In the second anodization treatment of step (c), the aluminum-containing object after step (b) is immersed in a second electrolyte different from the first electrolyte for implementation, and step (c) includes the following sub-steps: sub-step (c1) and sub-step (c2). In sub-step (c1), the aluminum-containing object after step (b) is completely immersed in the second electrolyte for the reaction time of the second anodization treatment to form the second aluminum oxide film on the surface of the aluminum-containing object, and the reaction time is greater than the first predetermined time of the current signal. In sub-step (c2), the aluminum-containing object after step (c1) is gradually removed from the second electrolyte at a preset moving rate, so that the aluminum-containing object still immersed in the second electrolyte continues to undergo the second anodization treatment to continuously form and thicken the second aluminum oxide film immersed in the second electrolyte on the surface of the aluminum-containing object until the aluminum-containing object is completely removed from the second electrolyte.

[0012] The method for preparing an aluminum-containing photonic crystal according to the present invention, each periodic current signal when implementing step (b) sequentially includes a first predetermined time, a second predetermined time, a third predetermined time, and a fourth predetermined time. The first predetermined time of step (b) is to provide a constant current signal with a first current value to the aluminum-containing object. The second predetermined time of step (b) is to provide a decreasing current signal that gradually decreases from the first current value to a second current value to the aluminum-containing object. The third predetermined time of step (b) is to provide a constant current signal with the second current value to the aluminum-containing object. The fourth predetermined time of step (b) is to provide a rapidly increasing current signal that rapidly increases from the second current value to the first current value to the aluminum-containing object, and after the third predetermined time of the Nth periodic current signal is implemented, the constant current signal with the second current value provided to the aluminum-containing object is directly removed.

[0013] The method for preparing an aluminum-containing photonic crystal according to the present invention further includes step (a') between step (a) and step (b). In step (a), the first pretreatment sequentially includes degreasing and sandblasting. Step (a') is to perform a second pretreatment on the aluminum-containing object after sandblasting, which sequentially includes degreasing, alkali washing, pre-acid pickling, chemical polishing, and post-acid pickling.

[0014] The second object of the present invention is to provide an aluminum-containing photonic crystal product obtained by the foregoing preparation method.

[0015] The aluminum-containing photonic crystal article of the present invention includes an aluminum-containing object, N first aluminum oxide films, and a second aluminum oxide film. The N first aluminum oxide films are sequentially stacked above the surface of the aluminum-containing object along a first direction. The first direction refers to the direction from the first aluminum oxide film towards the aluminum-containing object. Each of the first aluminum oxide films has a plurality of first nanopore structures extending along the first direction and arranged at intervals from each other in a second direction substantially perpendicular to the first direction. The second aluminum oxide film is stacked between the Nth first aluminum oxide film in the first aluminum oxide films and the surface of the aluminum-containing object. The second aluminum oxide film has a plurality of second nanopore structures extending along the first direction and arranged at intervals in the second direction. Each of the second nanopore structures has an increasing pore diameter section connecting the first nanopore structure of the Nth first aluminum oxide film, and an equal pore diameter section connecting each increasing pore diameter section and the surface of the aluminum-containing object. In the present invention, the first aluminum oxide film and the first nanopore structure therein jointly define a first photonic crystal, and the second aluminum oxide film and the second nanopore structure therein jointly define a second photonic crystal. In addition, the thickness of the second aluminum oxide film is greater than the total thickness of the first aluminum oxide films.

[0016] In the aluminum-containing photonic crystal article of the present invention, the thickness of the second aluminum oxide film is at least greater than or equal to 5 μm.

[0017] In the aluminum-containing photonic crystal article of the present invention, the first nanopore structure of each first aluminum oxide film sequentially has a first section, a second section, a plurality of third sections, and a fourth section along the first direction. The first section of each first nanopore structure is an equal pore diameter nanopore. The second section of each first nanopore structure is a decreasing pore diameter nanopore connecting each first section and gradually narrowing along the first direction. Each of the third sections of each first nanopore structure is an equal pore diameter nanopore and is not connected to the second section corresponding thereto. The pore diameter of the equal pore diameter nanopore of the third section of each first nanopore structure is smaller than the pore diameter of the equal pore diameter nanopore of each first section, and the third sections of each first nanopore structure are arranged at intervals from each other in the second direction and extend along the first direction. The fourth section of each first nanopore structure is an increasing pore diameter nanopore connecting each third section and rapidly increasing along the first direction. The first section and the fourth section of each first nanopore structure in the first direction are respectively connected to the fourth section and the first section of the two adjacent first aluminum oxide films, and the fourth section of each first nanopore structure is connected to the third section corresponding thereto. Each first nanopore structure in the Nth first aluminum oxide film does not have the fourth section, and the equal pore diameter nanopores of each third section of each first nanopore structure in the Nth first aluminum oxide film are connected to the increasing pore diameter sections of the second aluminum oxide film.

[0018] In the alumin-containing photonic crystal article of the present invention, the second alumina film sequentially has a first part and a second part connected to each other along a third direction different from the second direction, and the thickness of the second part of the second alumina film is greater than the thickness of the first part of the second alumina film.

[0019] In the alumin-containing photonic crystal article of the present invention, the second alumina film further sequentially has a third part, a fourth part, and a fifth part connected to each other along the third direction, and the third part of the second alumina film is connected to its second part. The thickness of the third part of the second alumina film is greater than the thickness of the second part of the second alumina film, the thickness of the fourth part of the second alumina film is greater than the thickness of the third part of the second alumina film, and the thickness of the fifth part of the second alumina film is greater than the thickness of the fourth part of the second alumina film.

[0020] In the alumin-containing photonic crystal article of the present invention, the thickness of the second alumina film gradually increases along a third direction different from the second direction.

[0021] The beneficial effect of the present invention is that the interference generated after an external light source travels into the second nanopore structure inside the second alumina film can be adjusted by the second anodization in step (c), so as to improve the saturation and brightness of the color presented by the article.

[0022] The third object of the present invention is to provide a method for preparing an alumin-containing photonic crystal capable of enhancing color saturation and brightness.

[0023] The method for preparing an alumin-containing photonic crystal of the present invention includes the following steps: step (a), step (b), and step (c). In step (a), a pretreatment is performed on the alumin-containing object to remove contaminants on the surface of the alumin-containing object. In step (b), a first anodization is performed on the alumin-containing object after step (a). The first anodization provides a plurality of periodic current signals to the alumin-containing object, thereby generating multiple layers of first alumina films on the surface of the alumin-containing object. Each of the first alumina films has a plurality of first nanopore structures arranged at intervals inside. In step (c), a second anodization is performed on the alumin-containing object after step (b), thereby generating a second alumina film between the lowermost layer of the multiple layers of first alumina films and the surface of the alumin-containing object. The second alumina film has a plurality of second nanopore structures arranged at intervals inside. In the present invention, the second anodization provides a current signal to the alumin-containing object within a first predetermined time and a second predetermined time. Within the first predetermined time, the current signal slowly increases from 0 to a predetermined current value, and the predetermined current value is greater than the maximum current value of the periodic current signal in the first anodization. Within the second predetermined time, the current signal is a constant current signal maintaining the predetermined current value.

[0024] The beneficial effects of the present invention are as follows: The periodic current signal obtained through the first anodization is used to determine the basic color that the first aluminum oxide film prepared thereby can exhibit. When an external light source travels into the first nanopore structure inside the first aluminum oxide film, interference occurs, causing the film to exhibit different colors at different angles. At the same time, the process parameters of the second anodization are used to adjust the interference generated when the external light source travels into the second nanopore structure inside the second aluminum oxide film, so as to enhance the color saturation of the product. Description of the Drawings

[0025] Figure 1 is a flowchart illustrating a first embodiment of a method for preparing an aluminum-containing photonic crystal according to the present invention;

[0026] Figure 2 is a current-versus-time graph illustrating a first periodic current signal during a first anodization performed in step (b) of the first embodiment of the present invention;

[0027] Figure 3 is a schematic diagram of an element manufacturing process illustrating N layers of first aluminum oxide films obtained after N periodic current signals in step (b) of the first embodiment of the present invention are implemented;

[0028] Figure 4 is Figure 3 a partial enlarged schematic diagram illustrating the specific structure of a first photonic crystal in the first embodiment of the present invention;

[0029] Figure 5 is a current-versus-time graph illustrating N periodic current signals during the first anodization in step (b) and a current signal during a second anodization in step (c) of the first embodiment of the present invention;

[0030] Figure 6 is a schematic diagram illustrating an aluminum-containing photonic crystal product obtained after step (c) of the first embodiment of the present invention is implemented;

[0031] Figure 7 is a schematic diagram of an element manufacturing process illustrating that step (c) of a second embodiment of a method for preparing an aluminum-containing photonic crystal according to the present invention includes one step (c1) and one step (c2);

[0032] Figure 8 is a schematic diagram illustrating an aluminum-containing photonic crystal product obtained after step (c) of the second embodiment of the present invention is implemented;

[0033] Figure 9It is a schematic diagram of a component manufacturing process, showing that step (c) of the method for preparing an aluminum-containing photonic crystal according to the present invention further includes one step (c3), one step (c4), and one step (c5);

[0034] Figure 10 It is a schematic diagram showing the aluminum-containing photonic crystal product obtained after implementing step (c) of the third embodiment of the present invention;

[0035] Figure 11a Illustrating the periodic current density signal during the implementation of a first anodization in a specific example 1 (E1) of the method for preparing an aluminum-containing photonic crystal according to the present invention, Figure 11b Illustrating the current density signal during the implementation of a second anodization in the specific example 1 (E1) of the present invention;

[0036] Figure 12a It is a top view (0-degree angle) image showing the aluminum-containing photonic crystal product obtained after implementing the preparation method of the specific example 1 (E1) of the present invention, Figure 12b It is an inclined view (45-degree angle) image showing that the color presented by the aluminum-containing photonic crystal product of the specific example 1 (E1) of the present invention at a 45-degree angle is significantly different from the color presented at a 0-degree angle;

[0037] Figure 13 Illustrating the periodic current density signal during the implementation of a first anodization in a specific example 2 (E2) of the method for preparing an aluminum-containing photonic crystal according to the present invention;

[0038] Figure 14a It is a top view (0-degree angle) image showing the aluminum-containing photonic crystal product obtained after implementing the preparation method of the specific example 2 (E2) of the present invention, Figure 14b It is an inclined view (45-degree angle) image showing that the color presented by the aluminum-containing photonic crystal product of the specific example 2 (E2) of the present invention at a 45-degree angle is significantly different from the color presented at a 0-degree angle;

[0039] Figure 15 It is a top view (0-degree angle) image showing the aluminum-containing photonic crystal product obtained from a specific example 3 (E3) of the method for preparing an aluminum-containing photonic crystal according to the present invention;

[0040] Figure 16 It is a top view (0-degree angle) image showing the aluminum-containing photonic crystal product obtained from a specific example 4 (E4) of the method for preparing an aluminum-containing photonic crystal according to the present invention;

[0041] Figure 17a It is a top view (0-degree angle) image showing the aluminum-containing photonic crystal product obtained from a specific example 5 (E5) of the method for preparing an aluminum-containing photonic crystal according to the present invention, Figure 17bAn image of a tilted perspective (45-degree angle) shows that the color presented by the aluminum-containing photonic crystal product of this specific example 5 (E5) of the present invention at a 45-degree angle is significantly different from the color presented at a 0-degree angle; and

[0042] Figure 18 It is a CIELAB color space (international commission on illumination L*a*b*) diagram, showing the color saturation of these specific examples (E1, E2) of the present invention. Detailed Description of the Invention

[0043] The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

[0044] Refer to Figure 1 , a first embodiment of a method for preparing an aluminum-containing photonic crystal and its product of the present invention includes the following steps: a step (a), a step (a'), a step (b), and a step (c).

[0045] This step (a) is to perform a first pretreatment on the aluminum-containing object 2 as shown in Figure 3 to remove contaminants (not shown in the figure) on a surface 211 of the aluminum-containing object 2. In step (a) of this first embodiment, this first pretreatment sequentially includes degreasing and sandblasting.

[0046] This step (a') is to sequentially perform a second pretreatment on the sandblasted aluminum-containing object 2, including degreasing, alkali washing, pre-acid pickling, chemical polishing, and post-acid pickling.

[0047] This step (b) is to perform a first anodization on the aluminum-containing object 2 after step (a), thereby generating N layers of first aluminum oxide films 3 stacked in sequence along a first direction X on the surface 211 of the aluminum-containing object 2. The first direction X is as shown in Figure 3 and Figure 4 shown, referring to the direction from the first aluminum oxide film 3 towards the aluminum-containing object 2. Each first aluminum oxide film 3 has a plurality of first nanopore structures 301 extending along the first direction X and arranged at intervals from each other along a second direction Y substantially perpendicular to the first direction X. When performing the first anodization in step (b), a periodic current signal is provided to the aluminum-containing object 2 N times. Specifically (please see Figure 2), each periodic current signal during the implementation of step (b) sequentially includes a first predetermined time pt1, a second predetermined time pt2, a third predetermined time pt3, and a fourth predetermined time pt4. The first predetermined time pt1 of step (b) provides a constant current signal with a first current value to the aluminum-containing object 2. The second predetermined time pt2 of step (b) provides a decreasing current signal to the aluminum-containing object 2 that gradually decreases from the first current value to a second current value. The third predetermined time pt3 of step (b) provides a constant current signal with the second current value to the aluminum-containing object 2. The fourth predetermined time of step (b) provides a rapidly increasing current signal to the aluminum-containing object 2 that rapidly increases from the second current value to the first current value, and after the third predetermined time pt3 of the Nth periodic current signal is implemented, the constant current signal with the second current value provided to the aluminum-containing object 2 is directly removed.

[0048] Specifically, the first alumina film 3 obtained by the first anodization in step (b) of the first embodiment of the present invention is as Figure 3 and Figure 4 shown. The first nanopore structure 301 of each first alumina film 3 sequentially has a first section 3011, a second section 3012, a plurality of third sections 3013, and a fourth section 3014 along the first direction X. The first section 3011 of each first nanopore structure 301 is a nanopore with an equal pore diameter. The second section 3012 of each first nanopore structure 301 is a nanopore with a decreasing pore diameter that connects each first section 3011 and gradually shrinks along the first direction X. Each third section 3013 of each first nanopore structure 301 is a nanopore with an equal pore diameter. The pore diameter of the equal-pore-diameter nanopores in the third section 3013 of each first nanopore structure 301 is smaller than the pore diameter of the equal-pore-diameter nanopores in each first section 3011, and the third sections 3013 of each first nanopore structure 301 are arranged at intervals along the second direction Y and extend along the first direction X, and are not connected to the corresponding second sections 3012. The fourth section 3014 of each first nanopore structure 301 is a nanopore with a rapidly increasing pore diameter that connects each third section 3013 and rapidly increases along the first direction X.

[0049] It should be noted that the first nanopore structure 301 in each first alumina film 3 corresponds to each periodic current signal during the implementation of step (b). Therefore, the first section 3011, the second section 3012, the third section 3013, and the fourth section 3014 of the first nanopore structure 301 in each first alumina film 3 respectively correspond to the current signals of the first predetermined time pt1, the second predetermined time pt2, the third predetermined time pt3, and the fourth predetermined time pt4 of each periodic current signal.

[0050] Referring further to Figure 2 andFigure 3 Specifically, the current signal based on the first predetermined time pt1 of each periodic current signal is a constant current signal having the first current value. Therefore, the first section 3011 of each first nanopore structure 301 is a nanopore with an equal pore diameter extending along the first direction X.

[0051] In addition, the current signal based on the second predetermined time pt2 of each periodic current signal is a decreasing current signal that gradually decreases from the first current value to the second current value. Therefore, the second section 3012 of each first nanopore structure 301 is connected to the corresponding first section 3011 and is a nanopore with a decreasing pore diameter that gradually narrows along the first direction X.

[0052] The current signal based on the third predetermined time pt3 of each periodic current signal is a constant current signal having the second current value. Therefore, the third section 3013 of each first nanopore structure 301 extends along the first direction X and is arranged at intervals from each other along the second direction Y perpendicular to the first direction X. The third section 3013 of each first nanopore structure 301 is not connected to the corresponding second section 3012. The nanopores of each third section 3013 of each first nanopore structure 301 have an equal pore diameter, and the pore diameter of the nanopores of each third section 3013 is smaller than the pore diameter of the nanopores of each first section 3011.

[0053] Furthermore, the current signal based on the fourth predetermined time pt4 of each periodic current signal is a rapidly increasing current signal that rapidly rises from the second current value to the first current value. Therefore, the fourth section 3014 of each first nanopore structure 301 extends along the first direction X and is a nanopore with a rapidly increasing pore diameter that rapidly increases along the first direction X. As Figure 4 shown, the first section 3011 and the fourth section 3014 of each first nanopore structure 301 in the first direction X are respectively connected to the fourth section 3014 and the first section 3011 of the two adjacent first alumina films 3, and the fourth section 3014 of each first nanopore structure 301 is connected to the corresponding third section 3013. In addition, as Figure 3 shown, the first layer of the first alumina film 3 and the corresponding first nanopore structure 301 completed by the first periodic current signal after performing the step (b) are the farthest from the surface 211 of the aluminum-containing object 2, and the Nth layer of the first alumina film 3 and the corresponding first nanopore structure 301 completed by the Nth periodic current signal after performing the step (b) are in direct contact with the surface 211 of the aluminum-containing object 2.

[0054] In addition, after the third predetermined time pt3 of the Nth periodic current signal is completed, the constant current signal of the second current value provided to the aluminum-containing object 2 is directly removed. Therefore, each first nanopore structure 301 in the Nth layer of the first alumina film 3 in the first alumina film 3 does not have the fourth section 3014.

[0055] It is worth mentioning that for the first alumina film 3 prepared by the method of the first embodiment of the present invention, since it is a decreasing current signal at the second predetermined time pt2 of each periodic current signal when performing step (b), it can provide an inclined slope between each first nanopore structure 301 and the entity (each first alumina film 3) (that is, the second section 3012 of each first nanopore structure 301). Therefore, due to the aforementioned slope, the first alumina film 3 can present different colors at different viewing angles.

[0056] Refer to Figure 5 And Figure 6 , in step (c), a second anodization is performed on the aluminum-containing object 2 after step (b), so as to generate a second alumina film 4 between the Nth layer of the first alumina film 3 in the first alumina film 3 and the surface 211 of the aluminum-containing object 2. The second alumina film 4 has a plurality of second nanopore structures 401 extending along the first direction X and arranged at intervals along the second direction Y. Specifically, in the first anodization of step (b) of the first embodiment, the aluminum-containing object 2 is immersed in a first electrolyte (not shown in the figure) for implementation. In the second anodization of step (c) of the first embodiment, the aluminum-containing object 2 after step (b) is immersed in a second electrolyte 62 different from the first electrolyte (please see Figure 7 ). When performing the second anodization of step (c) of the first embodiment, a current signal is provided to the aluminum-containing object 2. The current signal of step (c) sequentially includes a first predetermined time and a second predetermined time. The first predetermined time of step (c) is to provide a slowly increasing current signal to the aluminum-containing object 2 that slowly increases from 0 to a predetermined current value, and the predetermined current value of the slowly increasing current signal is greater than a maximum current value of each periodic current signal (that is, the first current value of each periodic current signal) as shown in Figure 5 . The second predetermined time of step (c) is to provide a constant current signal with the predetermined current value to the aluminum-containing object 2. Preferably, in step (c), an increasing rate of the slowly increasing current signal is to increase the current density value from 0 mA / cm 2 to 40 mA / cm 2 within a time of 100 seconds to 600 seconds.

[0057] From the detailed description of the above step (c), it can be seen that the second alumina film 4 is asFigure 6 As shown, between the Nth layer of the first alumina film 3 stacked in the first alumina film 3 and the surface 211 of the aluminum-containing object 2. Specifically, each second nanopore structure 401 inside the second alumina film 4 also corresponds to the current signal during the implementation of step (c). Therefore, each second nanopore structure 401 inside the second alumina film 4 has an increasing pore diameter section 4011 connecting the first nanopore structure 301 of the Nth layer of the first alumina film 3 (corresponding to the gradually increasing current signal of the first predetermined time), and an equal pore diameter section 4012 connecting each increasing pore diameter section 4011 and the surface 211 of the aluminum-containing object 2 (corresponding to the constant current signal of the second predetermined time). In addition, the equal pore diameter nanopores of each third section 3013 of each first nanopore structure 301 of the Nth layer of the first alumina film 3 are connected to each increasing pore diameter section 4011 of the second alumina film 4. In the first embodiment of the present invention, the first alumina film 3 and the first nanopore structure 301 inside it jointly define a first photonic crystal 300, and the second alumina film 4 and the second nanopore structure 401 inside it jointly define a second photonic crystal 400. The thickness of the second alumina film 4 is greater than the total thickness of the first alumina film 3.

[0058] It is worth mentioning here that the method of the first embodiment of the present invention uses the process parameters of the first anodization in step (b) to determine the basic color that the obtained first alumina film 3 can present, and the first alumina film 3 presents different colors at different angles due to the interference generated after an external light source (not shown in the figure) travels into the first nanopore structure 301 inside it. At the same time, the method of the first embodiment of the present invention uses the process parameters of the second anodization in step (c) to adjust the interference generated after the external light source travels into the second nanopore structure 401 inside the second alumina film 4, so as to improve the saturation and brightness of the color presented by its products. Therefore, preferably, the thickness of the second alumina film 4 is at least greater than or equal to 5 μm.

[0059] Referring to Figure 7 and Figure 8 , a second embodiment of the method for preparing an aluminum-containing photonic crystal and its product of the present invention is substantially the same as the first embodiment, and the difference lies in that step (c) includes the following sub-steps: a sub-step (c1) and a sub-step (c2).

[0060] In the sub-step (c1), the aluminum-containing object 2 after step (b) is completely immersed in the second electrolyte 62 for a first reaction time t1 of the second anodization to form the second alumina film 4 on the surface 211 of the aluminum-containing object 2, and the first reaction time t1 is greater than the first predetermined time of the current signal in step (c).

[0061] In this step (c2), an automatic lifting mechanism (not shown in the figure) is used to move a first part 21 of the aluminum-containing object 2 after the step (c1) out of the second electrolyte 62 along a third direction Z different from the second direction Y (in the second embodiment, it is the height direction as shown) Figure 7 so that a remaining part of the aluminum-containing object 2 excluding the first part 21 continues to be immersed in the second electrolyte 62 for a second reaction time t2 of the second anodizing process, so as to continuously generate and thicken a second aluminum oxide film 4 on the surface 211 of the aluminum-containing object 2 that is immersed in the second electrolyte 62.

[0062] Therefore, as shown Figure 8 the second aluminum oxide film 4 of the product obtained by the method of the second embodiment of the present invention has a first part 41 and a second part 42 that are connected to each other along the third direction Z, and the thickness of the second part 42 of the second aluminum oxide film 4 is greater than the thickness of the first part 41 of the second aluminum oxide film 4.

[0063] Referring to Figure 9 and Figure 10 a third embodiment of the method for preparing an aluminum-containing photonic crystal and its product of the present invention is substantially the same as the second embodiment, the difference being that the step (c) of the second embodiment further includes the following sub-steps: a sub-step (c3), a sub-step (c4), and a sub-step (c5).

[0064] In this sub-step (c3), the automatic lifting mechanism (not shown in the figure) is used to move a second part 22 of the aluminum-containing object 2 after the step (c2) out of the second electrolyte 62 along the third direction Z, so that a remaining part of the aluminum-containing object 2 excluding the first part 21 and the second part 22 continues to be immersed in the second electrolyte 62 for a third reaction time t3 of the second anodizing process, so as to continuously generate and thicken a second aluminum oxide film 4 on the surface 211 of the aluminum-containing object 2 that is immersed in the second electrolyte 62.

[0065] In this sub-step (c4), the automatic lifting mechanism is used to move a third part 23 of the aluminum-containing object 2 after the step (c3) out of the second electrolyte 62 along the third direction Z, so that a remaining part of the aluminum-containing object 2 excluding the first part 21, the second part 22, and the third part 23 continues to be immersed in the second electrolyte 62 for a fourth reaction time t4 of the second anodizing process, so as to continuously generate and thicken a second aluminum oxide film 4 on the surface 211 of the aluminum-containing object 2 that is immersed in the second electrolyte 62.

[0066] In this step (c5), the automatic lifting mechanism is used to move a fourth part 24 of the aluminum-containing object 2 out of the second electrolyte 62 along the third direction Z after step (c4), so that a remaining part of the aluminum-containing object 2 other than the first part 21, the second part 22, the third part 23, and the fourth part 24 continues to be immersed in the second electrolyte 62 for a fifth reaction time t5 of the second anodizing process, so as to continuously generate and thicken the second aluminum oxide film 4 on the surface 211 of the aluminum-containing object 2 that is immersed in the second electrolyte 62.

[0067] Therefore, as Figure 10 shown, the second aluminum oxide film 4 of the product prepared by the method of the third embodiment of the present invention further sequentially has a third part 43, a fourth part 44, and a fifth part 45 that are connected to each other along the third direction Z, and the third part 43 of the second aluminum oxide film 4 is connected to its second part 42. The thickness of the third part 43 of the second aluminum oxide film 4 is greater than the thickness of the second part 42 of the second aluminum oxide film 4, the thickness of the fourth part 44 of the second aluminum oxide film 4 is greater than the thickness of the third part 43 of the second aluminum oxide film 4, and the thickness of the fifth part of the second aluminum oxide film is greater than the thickness of the fourth part of the second aluminum oxide film.

[0068] A fourth embodiment of the method for preparing an aluminum-containing photonic crystal of the present invention is substantially the same as the first embodiment, and the difference is that step (c) of the fourth embodiment includes the following sub-steps: a sub-step (c1), and a sub-step (c2). In the sub-step (c1) of the fourth embodiment, the aluminum-containing object 2 after step (b) is completely immersed in the second electrolyte 62 for a reaction time of the second anodizing process to generate the second aluminum oxide film 4 on the surface 211 of the aluminum-containing object 2, and the reaction time is greater than the first predetermined time of the current signal in step (c). In the sub-step (c2) of the fourth embodiment, the automatic lifting mechanism (not shown in the figure) is used to gradually move the aluminum-containing object 2 out of the second electrolyte 62 along the third direction Z at a preset moving rate, so that the aluminum-containing object 2 still immersed in the second electrolyte 62 continuously undergoes the second anodizing process to continuously generate and thicken the second aluminum oxide film 4 on the surface 211 of the aluminum-containing object 2 that is immersed in the second electrolyte 62 until the aluminum-containing object 2 is completely removed from the second electrolyte 62.

[0069] Therefore, the thickness of the second aluminum oxide film 4 of the product prepared by the method of the fourth embodiment of the present invention gradually increases along the third direction Z (not shown in the figure).

[0070] In other embodiments, (a) a pretreatment is performed on the aluminum-containing object 2 to remove contaminants on the surface 211 of the aluminum-containing object 2. (b) A first anodizing treatment is performed on the aluminum-containing object 2 after the step (a). The first anodizing treatment provides a plurality of periodic current signals to the aluminum-containing object 2, thereby generating a plurality of layers of first aluminum oxide films 3 on the surface 211 of the aluminum-containing object 2. Each of the first aluminum oxide films 3 has a plurality of first nanopore structures 301 arranged at intervals. (c) A second anodizing treatment is performed on the aluminum-containing object 2 after the step (b), thereby generating a second aluminum oxide film 4 between the lowermost layer of the plurality of layers of first aluminum oxide films 3 and the surface 211 of the aluminum-containing object 2. The second aluminum oxide film 4 has a plurality of second nanopore structures 401 arranged at intervals. In the present invention, the second anodizing treatment provides a current signal to the aluminum-containing object 2 within a first predetermined time and a second predetermined time. Within the first predetermined time, the current signal slowly increases from 0 to a predetermined current value, and the predetermined current value is greater than the maximum current value of the periodic current signal of the first anodizing treatment. Within the second predetermined time, the current signal is a constant current signal maintaining the predetermined current value.

[0071] The present invention provides detailed descriptions and images of methods and products of several specific examples to assist in explaining the efficacy of the method of the present invention.

[0072] <Specific Example 1 (E1)>

[0073] A specific example 1 (E1) of the method for preparing an aluminum-containing photonic crystal of the present invention and the product obtained by the method are performed on a 6063 square aluminum alloy plate with a side length of 40 mm and a thickness of 6 mm, and are implemented according to the first embodiment.

[0074] First, a first pretreatment is performed on an aluminum alloy plate of the specific example 1 (E1). Specifically, the aluminum alloy plate of the specific example 1 (E1) is first immersed in a degreasing solution containing 1 to 10 vol% at 40 to 70 °C for ultrasonic vibration cleaning for 1 to 10 minutes, then washed with pure water, dried, and then placed in an oven at 75 to 100 °C for drying for 20 to 30 minutes to complete the degreasing of the first pretreatment. After completing the degreasing of the first pretreatment, the aluminum alloy plate of the specific example 1 (E1) is surface blasted with aluminum oxide balls (ball diameter 40 to 500 μm) at a pressure of 1 to 5 kg / cm 2 pressure.

[0075] Next, the aluminum alloy plate of this specific example 1 (E1) is subjected to this second pretreatment. Specifically, first, the aluminum alloy plate is immersed in a degreasing solution at 40 to 70 °C containing 1 to 10 vol% for ultrasonic vibration cleaning for 1 to 10 minutes, and then washed with pure water to complete the degreasing of this second pretreatment. After the aluminum alloy plate that has completed the degreasing of this second pretreatment is immersed in an alkaline solution containing 1 to 10 wt.% of sodium hydroxide (NaOH) at 40 to 70 °C for 30 to 120 seconds, it is washed with pure water to complete the alkali washing of this second pretreatment. After the aluminum alloy plate that has completed the alkali washing of this second pretreatment is immersed in an acidic solution containing nitric acid (HNO3) at 20 to 50 °C for 1 to 5 minutes and then washed with pure water, the pre-acid washing of this second pretreatment is completed; wherein, the acidic solution is composed of a solution with a volume ratio of nitric acid: deionized water of 1 to 5: 9 to 5. After the aluminum alloy plate that has completed the pre-acid washing of this second pretreatment is immersed in a phosphoric acid (H3PO4) solution at 50 to 85 °C with a concentration of 50 to 85 wt.% for 10 to 300 seconds, it is washed with pure water to complete the chemical polishing of this second pretreatment. After the aluminum alloy plate that has completed the chemical polishing of this second pretreatment is immersed in the pickling solution for 1 to 5 minutes, it is washed with pure water to complete the post-acid washing of this second pretreatment.

[0076] Subsequently, a first anodizing treatment is applied to the aluminum alloy plate of this specific example 1 (E1). Preferably, in this specific example 1 (E1), sulfuric acid (H2SO4) with a concentration of 0.5 to 3 M is used as the first electrolyte solution. With the aluminum alloy plate as the anode and a lead plate as the cathode, a periodic current signal is provided to the aluminum alloy plate 30 to 300 times at a temperature of -5 to 10 °C to perform its first anodizing treatment, and 30 to 300 layers of a first aluminum oxide film are formed on the surface of the aluminum alloy plate, and each first aluminum oxide film has a plurality of first nanopore structures. More preferably, the total time of each cycle is between 710 and 900 seconds; the first predetermined time pt1 and its corresponding current density (J1) of each cycle are respectively between 100 and 150 seconds and between 1 and 5 mA / cm 2 ; the second predetermined time pt2 and its corresponding current density decreasing rate (J2) of each cycle are respectively between 10 and 100 seconds and between 0.009 and 0.09 mA·cm -2 ·s -1 ; the third predetermined time pt3 and its corresponding current density (J3) of each cycle are respectively between 600 and 650 seconds and between 0.1 and 0.5 mA / cm 2 ; The periodic current signal of this specific example 1 (E1) of the present invention is summarized as shown in Table 1 below. And Figure 11a as shown.

[0077] Table 1.

[0078] Total time per cycle (seconds) 800 <![CDATA[J1 (mA / cm 2 )]]> 2 pt1 (seconds) 125 <![CDATA[J2(mA·cm -2 ·s -1 ) # > 0.036 pt2 (seconds) 50 <![CDATA[J3 (mA / cm 2 )]]> 0.2 pt3 (seconds) 625 Number of cycles (times) 30

[0079] # The current density decreasing rate of the second predetermined time pt2.

[0080] Finally, the aluminum alloy plate after the first anodic treatment of the specific example 1 (E1) is fixed on the automatic lifting mechanism (not shown in the figure) to perform the second anodic treatment on the aluminum alloy plate of the specific example 1 (E1). In the specific example 1 (E1), the aluminum alloy plate and the lead plate are used as the anode and cathode respectively during the second anodic treatment. Preferably, the second anodic treatment is to completely immerse the aluminum alloy plate in a second electrolyte at room temperature (20 to 30 °C), and provide 0 mA / cm² to the aluminum metal plate within 100 seconds to 600 seconds. 2 Increased to 20 mA / cm² 2 of a gradually increasing current density (that is, a gradually increasing current signal of a predetermined current during the first predetermined time of the second anodic treatment), and then implement at a constant current density of 20 mA / cm² 2 for at least 900 to 5400 seconds. It should be noted here that the second electrolyte applicable to the specific example 1 (E1) of the present invention is a composite electrolyte mixed with an inorganic acid and an organic acid. The inorganic acid is selected from sulfuric acid, boric acid, and sulphamic acid. The organic acid is selected from 5-sulphosalicylic acid, hydroquinone, 1,5-naphthalenedisulphonic acid, 4-sulphophthalic acid, succinic acid, oxalic acid, citric acid, tartaric acid, or formic acid. More preferably, the second electrolyte of the specific example 1 (E1) is composed of an inorganic acid with a concentration between 0.1 and 1 wt% and an organic acid with a concentration between 5 and 20 wt%. As Figure 11b shown, the gradually increasing current density of the specific example 1 (E1) of the present invention increases from 0 to 20 mA / cm² within 600 seconds, 2 and the constant current density is implemented for 3000 seconds under the condition of 20 mA / cm². 2

[0081] From Figure 12a it can be clearly seen that the top view (0-degree angle) image of the specific example 1 (E1) of the present invention after the second anodic treatment shows a distinct red color, while its image at the tilt angle (45-degree angle) shows a distinct yellow-green color (please seeFigure 12b ). It is confirmed that the color saturation of the aluminum-containing photonic crystal product produced by the present invention can be increased by performing the second anodizing treatment, so it can be expected that the corresponding brightness can also be improved.

[0082] <Concrete example 2 (E2)>

[0083] A specific example 2 (E2) of the method for preparing aluminum-containing photonic crystals of the present invention and the aluminum-containing photonic crystal product obtained by the method are substantially the same as the specific example 1 (E1), and the difference lies in the detailed conditions of the first anodizing treatment of the specific example 2 (E2). Preferably, the total time of each cycle of the first anodizing treatment of the specific example 2 (E2) is between 560 and 750 seconds; the first predetermined time pt1 of each cycle and the corresponding current density (J1) are between 75 and 125 seconds and between 1 and 5 mA / cm 2 The second predetermined time pt2 of each cycle and its corresponding current density deceleration rate (J2) are respectively between 10 and 100 seconds and between 0.009 and 0.09 mA cm -2 ·s -1 The third predetermined time pt3 of each cycle and its corresponding current density (J3) are respectively between 475 and 525 seconds and between 0.1 and 0.5 mA / cm 2 The detailed conditions of the first anodizing treatment of the specific example 2 (E2) of the present invention are summarized in the following Table 2. Figure 13 .

[0084] Table 2.

[0085]

[0086]

[0087] # The current density decreasing rate during the second predetermined time pt2.

[0088] The product of the specific example 2 (E2) of the present invention after the first anodizing treatment and the second anodizing treatment is bright green in the top view (0 degree angle) (see Figure 14a ), while the image at an oblique angle (45 degrees) appears bright blue (see Figure 14b ). This confirms that the basic color of the product of Example 2 (E2) of the present invention is green (different from the basic color of the product of Example 1 (E1) which is red) due to the process parameters when performing the first anodizing treatment being different from those of Example 1 (E1), and can present different colors at different viewing angles. It also confirms that the color saturation of the product of Example 2 (E2) can be increased due to the second anodizing treatment, so it can be expected that the corresponding brightness can also be improved.

[0089] <Specific Example 3 (E3)>

[0090] A specific example 3 (E3) of the method for preparing an aluminum-containing photonic crystal of the present invention and the product prepared by the method are implemented according to the second embodiment. This specific example 3 (E3) is substantially the same as the specific example 2 (E2), the difference being that the second anodization is carried out in two stages and is implemented using a 6063 concentric circle aluminum alloy plate with an outer diameter, inner diameter and thickness of 30 mm, 2 mm and 1 mm respectively. When implementing the sub-step (c1) of the second anodization in this specific example 3 (E3), the aluminum alloy plate is completely immersed in the second electrolyte through the automatic lifting mechanism (not shown in the figure) for a first reaction time t1 of 1800 seconds, and when implementing the sub-step (c2) of the second anodization, the aluminum alloy plate is moved upward by 15 mm through the automatic lifting mechanism to remove the aluminum alloy plate 15 mm (that is, half of the aluminum alloy plate) from the second electrolyte, so that the remaining half of the aluminum alloy plate continues to be immersed in the second electrolyte for a second reaction time t2 of 900 seconds.

[0091] As is Figure 15 clearly visible, the top-down view (0-degree angle) image of this specific example 3 (E3) after the second anodization shows distinct two-stage colors of light green above and green below. It is confirmed that in addition to increasing the color saturation and brightness of the product of the present invention in this specific example 3 (E3) due to the implementation of the second anodization, two-stage colors can also be presented because the second anodization is carried out in two stages. It is worth mentioning that this specific example 3 (E3) of the present invention can replace the wet etching (i.e., the subtractive method) of the previous case 1 through the two-stage second anodization (i.e., the growing method), which can not only improve the color saturation and brightness of the product, but also does not require the use of the etchant in the previous case 1.

[0092] <Specific Example 4 (E4)>

[0093] A specific example 4 (E4) of the method for preparing an aluminum-containing photonic crystal according to the present invention and the product obtained by the method are implemented according to the third embodiment. This specific example 4 (E4) is substantially the same as the specific example 1 (E1) and the specific example 3 (E3), the difference being that the specific example 4 (E4) uses the same aluminum alloy plate as the specific example 3 (E3), and the first anodization is carried out using the process parameters of the specific example 1 (E1), while the second anodization is carried out in a five-stage manner at equal distances. Specifically, for the first reaction time t1, the second reaction time t2, the third reaction time t3, the fourth reaction time t4, and the fifth reaction time t5 in the sub-steps (c1), (c2), (c3), (c4), and (c5) of the second anodization of the specific example 4 (E4), they are respectively carried out for 900 seconds, 900 seconds, 900 seconds, 900 seconds, and 900 seconds.

[0094] As Figure 16 is clearly visible, the top-down view (0-degree angle) image of the specific example 4 (E4) after performing the five-stage second anodization at equal distances shows five distinct colors of red, orange, yellow, green, and blue from top to bottom.

[0095] <Specific example 5 (E5)>

[0096] A specific example 5 (E5) of the method for preparing an aluminum-containing photonic crystal according to the present invention and the product obtained by the method are implemented according to the fourth embodiment. This specific example 5 (E5) is substantially the same as the specific example 4 (E4), the difference being that the second anodization of the specific example 5 (E5) is carried out in an equal-speed displacement (equal-speed upward) manner. Specifically, when performing the sub-step (c1) of the second anodization of the specific example 5 (E5), the aluminum alloy plate is completely immersed in the second electrolyte through the automatic lifting mechanism (not shown in the figure) for a reaction time of 900 seconds, and when performing the sub-step (c2), the aluminum alloy plate is gradually moved out of the second electrolyte upward at a rising rate of 0.01 mm / s through the automatic lifting mechanism until the aluminum alloy plate still immersed in the second electrolyte is completely removed from the second electrolyte. It is worth mentioning that after the second anodization of the specific example 5 (E5) is completed, screen printing is also carried out to coat a layer with a pattern as Figure 17a and Figure 17b shown on the first aluminum oxide film of the specific example 5 (E5).

[0097] As Figure 17aAs can be seen, the overhead view (0-degree angle) image of the specific example 5 (E5) after performing the second anodic treatment of the constant velocity displacement (constant velocity upward) type shows a gradient color of distinct red, orange, yellow, green, and blue from top to bottom. Then, from Figure 17b As can be seen, the specific example 5 (E5) shows a gradient color of the blue-green system in the inclined view (45-degree angle) image.

[0098] The distribution of the products of the specific examples (E1 and E2) of the present invention in the CIELAB color space diagram can be seen in Figure 18 . After the specific examples (E1 and E2) perform their respective first anodic treatments, the corresponding CIE coordinate values all approach the center point representing low color saturation (please see Figure 18 in Figure 12a and Figure 14a marked positions). After the specific examples (E1 and E2) perform their respective second anodic treatments, the corresponding CIE coordinate values all move away from the center point (please see Figure 18 in Figure 12b and Figure 14b marked positions), indicating that the color saturation has been greatly improved.

[0099] Integrating the above detailed description, in the present invention, since the second predetermined time pt2 of each periodic current signal for performing the first anodic treatment is a decreasing current signal, an inclined slope can be provided between each first nanopore structure 301 and the entity (each first alumina film 3). That is, the second section 3012 of each first nanopore structure 301. Based on the aforementioned slope, the first alumina film 3 can present different colors at different viewing angles. In addition, through the second anodic treatment, the color saturation and brightness of the aluminum-containing photonic crystal products can also be improved.

[0100] In summary, the method for preparing an aluminum-containing photonic crystal and its products of the present invention can present different colors at different viewing angles, and can also improve the color saturation and brightness of its products. Therefore, the purpose of the present invention can indeed be achieved.

[0101] The above are only examples of the present invention, and the scope of implementation of the present invention cannot be limited thereby. All simple equivalent changes and modifications made according to the claims and the content of the specification of the present invention still fall within the scope covered by the patent of the present invention.

Claims

1. A method for preparing an aluminum-containing photonic crystal; characterized in that: It includes the following steps: Step (a): Apply a first pretreatment to the aluminum-containing object to remove contaminants on the surface of the aluminum-containing object; Step (b): Apply a first anodization to the aluminum-containing object after step (a), thereby generating N first alumina films stacked in sequence in a first direction on the surface of the aluminum-containing object. The first direction refers to the direction from the first alumina film towards the aluminum-containing object. Each first alumina film has a plurality of first nanopore structures extending in the first direction and spaced apart from each other in a second direction substantially perpendicular to the first direction; And Step (c): Apply a second anodization to the aluminum-containing object after step (b), thereby generating a second alumina film between the Nth first alumina film in the first alumina films and the surface of the aluminum-containing object. The second alumina film has a plurality of second nanopore structures extending in the first direction and spaced apart in the second direction; Wherein, when performing the first anodization in step (b), an N-time periodic current signal is provided to the aluminum-containing object; Wherein, when performing the second anodization in step (c), a current signal is provided to the aluminum-containing object. The current signal sequentially includes a first predetermined time and a second predetermined time. The first predetermined time in step (c) is to provide a gradually increasing current signal to the aluminum-containing object that slowly increases from 0 to a predetermined current value, and the predetermined current value of the gradually increasing current signal is greater than the maximum current value of each periodic current signal. The second predetermined time in step (c) is to provide a constant current signal with the predetermined current value to the aluminum-containing object.

2. The method for preparing an aluminum-containing photonic crystal according to claim 1, wherein: In this step (c), the increasing rate of the ramp-up current signal is such that the current density is increased from 0 mA / cm 2 to 40 mA / cm 2 in a time period from 100 seconds to 600 seconds.

3. The method for preparing an aluminum-containing photonic crystal according to claim 1, wherein: In the first anodization of step (b), the aluminum-containing object is immersed in a first electrolyte for implementation. In the second anodization of step (c), the aluminum-containing object after step (b) is immersed in a second electrolyte different from the first electrolyte for implementation, and step (c) includes the following sub-steps: Sub-step (c1): Completely immerse the aluminum-containing object after step (b) in the second electrolyte for a first reaction time of the second anodization to generate the second alumina film on the surface of the aluminum-containing object, and the first reaction time is greater than the first predetermined time of the current signal; And Sub-step (c2): Remove a first part of the aluminum-containing object after sub-step (c1) from the second electrolyte, and keep the remaining part of the aluminum-containing object except the first part immersed in the second electrolyte to continue the second reaction time of the second anodization, so as to continuously generate and thicken the second alumina film immersed in the second electrolyte on the surface of the aluminum-containing object.

4. The method for preparing an aluminum-containing photonic crystal according to claim 3, wherein: The second anodization in step (c) further includes the following sub-steps: Sub-step (c3): Remove a second part of the aluminum-containing object after sub-step (c2) from the second electrolyte, and keep the remaining part of the aluminum-containing object except the first part and the second part immersed in the second electrolyte to continue the third reaction time of the second anodization, so as to continuously generate and thicken the second alumina film immersed in the second electrolyte on the surface of the aluminum-containing object; In the next step (c4), the third part of the aluminum-containing object after step (c3) is removed from the second electrolyte, and the remaining part of the aluminum-containing object excluding the first part, the second part, and the third part is continuously immersed in the second electrolyte for a fourth reaction time of the second anodizing process, so as to continuously form and thicken a second aluminum oxide film on the surface of the aluminum-containing object that is immersed in the second electrolyte; and In the next step (c5), the fourth part of the aluminum-containing object after step (c4) is removed from the second electrolyte, and the remaining part of the aluminum-containing object excluding the first part, the second part, the third part, and the fourth part is continuously immersed in the second electrolyte for a fifth reaction time of the second anodizing process, so as to continuously form and thicken a second aluminum oxide film on the surface of the aluminum-containing object that is immersed in the second electrolyte.

5. The method for preparing an aluminum-containing photonic crystal according to claim 1, characterized in that: In the first anodizing process of step (b), the aluminum-containing object is immersed in a first electrolyte for implementation. In the second anodizing process of step (c), the aluminum-containing object after step (b) is immersed in a second electrolyte different from the first electrolyte for implementation, and step (c) includes the following sub-steps: In sub-step (c1), the aluminum-containing object after step (b) is completely immersed in the second electrolyte for the reaction time of the second anodizing process, so as to form the second aluminum oxide film on the surface of the aluminum-containing object, and the reaction time is greater than the first predetermined time of the current signal; and In sub-step (c2), the aluminum-containing object after step (c1) is gradually removed from the second electrolyte at a preset moving rate, so that the aluminum-containing object still immersed in the second electrolyte continuously undergoes the second anodizing process to continuously form and thicken the second aluminum oxide film on the surface of the aluminum-containing object that is immersed in the second electrolyte until the aluminum-containing object is completely removed from the second electrolyte.

6. The method for preparing an aluminum-containing photonic crystal according to claim 1, wherein: Each periodic current signal when implementing step (b) sequentially includes a first predetermined time, a second predetermined time, a third predetermined time, and a fourth predetermined time. The first predetermined time of step (b) provides a constant current signal with a first current value to the aluminum-containing object. The second predetermined time of step (b) provides a decreasing current signal that gradually decreases from the first current value to a second current value to the aluminum-containing object. The third predetermined time of step (b) provides a constant current signal with the second current value to the aluminum-containing object. The fourth predetermined time of step (b) provides a sudden increase current signal that rapidly rises from the second current value to the first current value to the aluminum-containing object, and after the third predetermined time of the Nth periodic current signal is implemented, the constant current signal with the second current value provided to the aluminum-containing object is directly removed.

7. The method for preparing an aluminum-containing photonic crystal according to claim 1, characterized in that: Between step (a) and step (b), there is also included step (a’). In step (a), the first pretreatment sequentially includes degreasing and sandblasting. Step (a’) sequentially performs a second pretreatment on the aluminum-containing object after sandblasting, including degreasing, alkali washing, pre-acid pickling, chemical polishing, and post-acid pickling.

8. An aluminum-containing photonic crystal article; characterized in that: Comprising: An aluminum-containing object; An N-layer first aluminum oxide film is sequentially stacked above the surface of the aluminum-containing object along a first direction, where the first direction is the direction from the first aluminum oxide film towards the aluminum-containing object. Each first aluminum oxide film has a plurality of first nanopore structures extending along the first direction and spaced apart from each other in a second direction substantially perpendicular to the first direction; and a second aluminum oxide film is stacked between the Nth-layer first aluminum oxide film in the first aluminum oxide films and the surface of the aluminum-containing object. The second aluminum oxide film has a plurality of second nanopore structures extending along the first direction and spaced apart in the second direction. Each second nanopore structure has an increasing pore diameter section connecting the first nanopore structure of the Nth-layer first aluminum oxide film, and an equal pore diameter section connecting each increasing pore diameter section and the surface of the aluminum-containing object; wherein, the first aluminum oxide film and the first nanopore structure inside it jointly define a first photonic crystal, and the second aluminum oxide film and the second nanopore structure inside it jointly define a second photonic crystal; and wherein, the thickness of the second aluminum oxide film is greater than the total thickness of the first aluminum oxide film.

9. The alumin-containing photonic crystal article according to claim 8, wherein: The thickness of the second aluminum oxide film is at least greater than or equal to 5 μm.

10. The alumin-containing photonic crystal article according to claim 8, wherein: The first nanopore structure of each first aluminum oxide film sequentially has a first section, a second section, a plurality of third sections, and a fourth section along the first direction. The first section of each first nanopore structure is an equal pore diameter nanopore; the second section of each first nanopore structure is a decreasing pore diameter nanopore connecting each first section and gradually shrinking along the first direction; each third section of each first nanopore structure is an equal pore diameter nanopore. The pore diameter of the equal pore diameter nanopore of each third section of each first nanopore structure is smaller than the pore diameter of the equal pore diameter nanopore of each first section, and the third sections of each first nanopore structure are spaced apart from each other in the second direction and extend along the first direction, and are not connected to the second section corresponding to each of them; the fourth section of each first nanopore structure is a rapidly increasing pore diameter nanopore connecting each third section and increasing rapidly along the first direction. The first section and the fourth section of each first nanopore structure in the first direction are respectively connected to the fourth section and the first section of the two adjacent first aluminum oxide films. The fourth section of each first nanopore structure is connected to the third section corresponding to each of them. The fourth section is not present in each first nanopore structure in the Nth-layer first aluminum oxide film, and the equal pore diameter nanopores of each third section of each first nanopore structure in the Nth-layer first aluminum oxide film are connected to the increasing pore diameter sections of the second aluminum oxide film.

11. The alumin-containing photonic crystal article according to claim 8, wherein: The second aluminum oxide film sequentially has a first part and a second part connected to each other along a third direction different from the second direction, and the thickness of the second part of the second aluminum oxide film is greater than the thickness of the first part of the second aluminum oxide film.

12. The alumin-containing photonic crystal article according to claim 11, wherein: The second aluminum oxide film further sequentially has a third part, a fourth part, and a fifth part that are connected to each other along the third direction, the third part of the second aluminum oxide film is connected to its second part, the thickness of the third part of the second aluminum oxide film is greater than the thickness of the second part of the second aluminum oxide film, the thickness of the fourth part of the second aluminum oxide film is greater than the thickness of the third part of the second aluminum oxide film, and the thickness of the fifth part of the second aluminum oxide film is greater than the thickness of the fourth part of the second aluminum oxide film.

13. The alumin-containing photonic crystal article according to claim 8, wherein: The thickness of the second aluminum oxide film gradually increases along a third direction different from the second direction.

14. A method for preparing an aluminum-containing photonic crystal; characterized in that: Comprising the following steps: (a) Performing a pretreatment on the aluminum-containing object to remove contaminants on the surface of the aluminum-containing object; (b) Performing a first anodization on the aluminum-containing object after the step (a), the first anodization providing a plurality of periodic current signals to the aluminum-containing object, thereby generating a plurality of layers of first aluminum oxide films on the surface of the aluminum-containing object, and each of the first aluminum oxide films has a plurality of first nanopore structures arranged at intervals from each other inside; and (c) Performing a second anodization on the aluminum-containing object after the step (b), thereby generating a second aluminum oxide film between the lowermost layer of the plurality of layers of first aluminum oxide films and the surface of the aluminum-containing object, and the second aluminum oxide film has a plurality of second nanopore structures arranged at intervals from each other inside; wherein, the second anodization provides a current signal to the aluminum-containing object within a first predetermined time and a second predetermined time, within the first predetermined time, the current signal slowly increases from 0 to a predetermined current value, and the predetermined current value is greater than the maximum current value of the periodic current signal of the first anodization, and within the second predetermined time, the current signal is a constant current signal maintaining the predetermined current value.

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