阅读说明：本技术 一种实现圆二色性的u型结构及其制备方法 (A kind of U-shaped structure and preparation method thereof for realizing circular dichroism ) 是由 张中月 景志敏 唐先龙 白瑜 李颖 于 2019-09-05 设计创作，主要内容包括：本发明涉及微纳光学技术领域,具体涉及一种实现圆二色性的U型结构及其制备方法,该结构由多个结构相同的周期单元平面连接而成,每个周期单元中包含有一个U型结构单元,每个结构单元包括横体Ⅰ、横体Ⅱ、竖体,横体Ⅰ的一端与竖体的一端垂直连接,横体Ⅱ的一端与竖体的另一端垂直连接,横体Ⅰ、横体Ⅱ、竖体均不在同一个水平面。先使用电子束曝光技术制备微纳结构模板,然后通过逆时针旋转模板基底,并改变电子束蒸发镀膜、倾斜角沉积技术中蒸发镀膜的倾斜角度、镀膜时间制备出具有不同高度差手性金属纳米结构。本发明具有不同高度差手性金属纳米结构,方法简单,成本低,可以应用于生物监测,对映体传感,偏振转换和光电子的圆偏振器。(The present invention relates to micronano optical technical fields, more particularly to a kind of U-shaped structure and preparation method thereof for realizing circular dichroism, the structure is formed by connecting by the identical periodic unit plane of multiple structures, it include a U-shaped structure unit in each periodic unit, each structural unit includes horizontal body I, horizontal body II, perpendicular body, one end of horizontal body I is vertical with one end of perpendicular body to be connect, and one end of horizontal body II is vertical with the other end of perpendicular body to be connect, and horizontal body I, horizontal body II, perpendicular body be not in the same horizontal plane.First micro-nano structure template is prepared using electron beam lithography, then by rotary template substrate counterclockwise, and change that electron beam evaporation deposition, tilt angle, the plated film time of evaporation coating are prepared with different height difference chiral metal nanostructure in glancing angle deposition technology.The present invention has different height difference chiral metal nanostructure, and method is simple, at low cost, can be applied to biological monitoring, enantiomer sensing, polarization conversion and photoelectronic circuit polarizer.)

1. a kind of U-shaped structure for realizing circular dichroism, which is characterized in that the structure is put down by the identical periodic unit of multiple structures Face is formed by connecting；Each periodic unit includes a U-shaped structure unit；Each structural unit includes horizontal body I (11), horizontal body II (12), perpendicular body (13)；One end of the horizontal body I (11) is vertical with one end of the perpendicular body (13) to be connect；It is described One end of horizontal body II (12) is vertical with the other end of the perpendicular body (13) to be connect；The horizontal body I (11), horizontal body II (12), perpendicular body (13) it is not at same level；The horizontal body I (11), horizontal body II (12), perpendicular body (13) are made of precious metal material Au.

2. a kind of U-shaped structure for realizing circular dichroism according to claim 1, which is characterized in that the horizontal body I (11) and The equal length of horizontal body II (12) and the perpendicular body (13)；The horizontal body I (11) and horizontal body II (12) and the perpendicular body (13) Width is equal；The height of the perpendicular body (13) is greater than the height of the horizontal body I (11), and the height of the horizontal body II (12) is greater than institute State the height of horizontal body I (11) and the perpendicular body (13).

3. the preparation method of -2 any U-shaped structures for realizing circular dichroism according to claim 1, which is characterized in that described The preparation method is as follows:

Step 1, prepare substrate: preparing ito glass substrate and clean drying；

Step 2, resist coating: photoresist spinner spin coating photoresist PMMA in substrate glasses is utilized；

Step 3, it dries: the substrate of step 2 coating PMMA photoresist being placed on hot plate and is dried；

Step 4, electron beam exposure structure graph: square structure array is designed on pattern generator, and uses electron beam exposure Technology is exposed figure to substrate obtained in step 3, the substrate after being exposed；When exposure, electron beam is to the structure The PMMA photoresist of visuals perform etching；

Step 5, develop: under room temperature, the substrate exposed in step 4 being put into impregnate in developer solution and is developed；

Step 6, it is fixed: step 5 being impregnated to the substrate after development and is put into fixing solution and impregnates fixing, takes substrate after the completion of fixing Out, with being dried with nitrogen；

Step 7, it dries: step 6 being impregnated after being fixed and the substrate of drying is placed on hot plate and dries；

Step 8, gold-plated preparation: the substrate dried after being fixed in step 7 is adhered on coating machine sample stage with vacuum rubber belt, is put Enter vacuum coating equipment, vacuumizes；

Step 9, gold-plated: to rotate counterclockwise formwork structure obtained in step 3 and carry out plated film；Detailed process are as follows: first Layer of Au is deposited using glancing angle deposition technology first along square structure bottom edge in plated film orientation (1)；Then it is rotated by 90 ° counterclockwise, Au is deposited using glancing angle deposition technology in the second plated film orientation (2)；It is rotated by 90 ° counterclockwise again, in third plated film orientation (3) benefit Layer of Au is deposited with glancing angle deposition technology；The time being deposited three times is different, ultimately forms the U-shaped knot with different height Structure；The first filming orientation (1), the second plated film orientation (2) and third plated film orientation (3) are orthogonal；

Step 10, cooling instrument, inflated with nitrogen take out sample；

Step 11, it removes PMMA photoresist: using lift-off technique, the sample that step 10 is taken out steeps in acetone, the time No less than 30min dissolves electron beam PMMA photoresist；

Step 12, dry up: the substrate after drying up the removing PMMA photoresist that step 11 obtains with nitrogen gun obtains the realization circle Dichromatic U-shaped structure.

4. the preparation method of the U-shaped structure according to claim 3 for realizing circular dichroism, which is characterized in that the step 1 Detailed process are as follows: prepare with a thickness of 1.0mm, length and width dimensions are the ito glass of 20.0mm × 20.0mm, and by the ITO of preparation Glass is put into cleaning solution and cleans, after deionized water ultrasound 15min, with acetone ultrasound 15min, then with alcohol ultrasound 15min, Deionized water ultrasound 5min is used later, is put into after finally being dried up with nitrogen gun spare in nitrogen cabinet.

5. the preparation method of the U-shaped structure according to claim 4 for realizing circular dichroism, which is characterized in that the step 2 Concrete operations are as follows: set the photoresist spinner whirl coating time as 1 minute, 4000 rpm of revolving speed, it is ensured that substrate surface photoresist is formed Even film.

6. a kind of preparation method of U-shaped structure for realizing circular dichroism according to claim 5, which is characterized in that described The concrete operations of step 3 and step 7 are as follows: hot plate is heated to 150 degrees Celsius, baking time is 3 minutes.

7. a kind of preparation method of U-shaped structure for realizing circular dichroism according to claim 6, which is characterized in that described The time that development is impregnated in step 5 is 1 minute.

8. a kind of preparation method of U-shaped structure for realizing circular dichroism according to claim 7, which is characterized in that described Developer solution is to be made with 3:1 with volume ratio from two pentanone of tetramethyl and isopropanol in step 5, and fixing is impregnated in the step 7 Time be 1 minute.

9. a kind of preparation method of U-shaped structure for realizing circular dichroism according to claim 8, which is characterized in that described The beginning condition of step 9 plated film is that the chamber pressure of vacuum coating equipment is lower than 3 × 10^-6Torr 。

Technical field

The present invention relates to micronano optical technical fields, and in particular to a kind of U-shaped structure for realizing circular dichroism and its preparation Method.

Background technique

A chiral etymology indicates the symmetry of structure, there is important meaning in a variety of subjects in Greek.If certain Object is different from its mirror image, then it is referred to as " chiral ", and its mirror image cannot be overlapped with the original, just as left hand with The right hand each other mirror image and can not overlap.Chirality is the essential characteristic of life process, and the organic molecule for constituting life entity is most It is all chiral molecules.

Chiral molecules chiral signal in nature is generally very weak.In recent years, researcher's discovery can use chiral gold Belong to the surface phasmon that nanostructure generates to realize the enhancing of chiral signal.Helical structure can produce annular electro due to it Stream, so that magnetic direction is parallel in threaded interior direction of an electric field, so as to generate very strong chiral electromagnetic field.But In It is relatively difficult experimentally directly to prepare helical structure.The chiral nanostructure of three-dimensional with difference in height is similar to spiral, therefore It can produce stronger chiral signal.However, it has been reported that the three-dimensional chiral nanostructure about preparation with difference in height Step is not easy relative to the preparation step of helical structure, and long preparation period, and input cost is high.

Summary of the invention

In order to solve the problems in the existing technology, the present invention utilizes electron beam lithography and glancing angle deposition technology Combination be prepared for different height difference chiral metal U-shaped nano structure.

The invention is realized by the following technical scheme:

A kind of U-shaped structure for realizing circular dichroism, the structure are formed by connecting by the identical periodic unit plane of multiple structures；Institute Stating each periodic unit includes a U-shaped structure unit；Each structural unit includes horizontal body I, horizontal body II, perpendicular body；Institute The one end for stating horizontal body I vertical with one end of the perpendicular body is connect；One end of the horizontal body II is vertical with the other end of the perpendicular body Connection；The horizontal body I, horizontal body II, perpendicular body are not at same level；The horizontal body I, horizontal body II, perpendicular body are by noble metal material Material Au is made.

Further, the equal length of the horizontal body I and horizontal body II and the perpendicular body；The horizontal body I and horizontal body II and institute The width for stating perpendicular body is equal；The height of the perpendicular body is greater than the height of the horizontal body I, and the height of the horizontal body II is greater than the cross The height of body I and the perpendicular body.

Further, realize the preparation method of the U-shaped structure of circular dichroism, which is characterized in that it is described the preparation method is as follows:

Step 1, prepare substrate: preparing ito glass substrate and clean drying；

Step 2, resist coating: photoresist spinner spin coating photoresist PMMA in substrate glasses is utilized；

Step 3, it dries: the substrate of step 2 coating PMMA photoresist being placed on hot plate and is dried；

Step 4, electron beam exposure structure graph: square structure array is designed on pattern generator, and uses electron beam exposure Technology is exposed figure to substrate obtained in step 3, the substrate after being exposed；When exposure, electron beam is to the structure The PMMA photoresist of visuals perform etching；

Step 5, develop: under room temperature, the substrate exposed in step 4 being put into impregnate in developer solution and is developed；

Step 6, it is fixed: step 5 being impregnated to the substrate after development and is put into fixing solution and impregnates fixing, takes substrate after the completion of fixing Out, with being dried with nitrogen；

Step 7, it dries: step 6 being impregnated after being fixed and the substrate of drying is placed on hot plate and dries；

Step 8, gold-plated preparation: the substrate dried after being fixed in step 7 is adhered on coating machine sample stage with vacuum rubber belt, is put Enter vacuum coating equipment, vacuumizes；Step 9, gold-plated: to rotate counterclockwise formwork structure obtained in step 3 and carry out plated film；Tool Body process are as follows: in the first filming orientation first along square structure bottom edge, layer of Au is deposited using glancing angle deposition technology；Then inverse Hour hands are rotated by 90 °, and Au is deposited using glancing angle deposition technology in the second plated film orientation；It is rotated by 90 ° counterclockwise again, in third plated film Layer of Au is deposited using glancing angle deposition technology in orientation；The time being deposited three times is different, and ultimately forming one has different height U-shaped structure；The first filming orientation, the second plated film orientation and third plated film orientation are orthogonal；

Step 10, cooling instrument, inflated with nitrogen take out sample.

Step 11, it removes PMMA photoresist: using lift-off technique, the sample that step 10 is taken out steeps in acetone, Time is no less than 30min, dissolves electron beam PMMA photoresist；

Step 12, dry up: the substrate after drying up the removing PMMA photoresist that step 11 obtains with nitrogen gun obtains the realization circle Dichromatic U-shaped structure.

Further, the detailed process of the step 1 are as follows: prepare with a thickness of 1.0mm, length and width dimensions be 20.0mm × The ito glass of 20.0mm, and the ito glass of preparation is put into cleaning solution and is cleaned, after deionized water ultrasound 15min, with third Ketone ultrasound 15min, then nitrogen is put into after finally being dried up with nitrogen gun later with deionized water ultrasound 5min with alcohol ultrasound 15min It is spare in gas holder.

Further, the concrete operations of the step 2 are as follows: set the photoresist spinner whirl coating time as 1 minute, revolving speed 4000 Rpm, it is ensured that substrate surface photoresist forms uniform film.

Further, the concrete operations of the step 3 and step 7 are as follows: hot plate is heated to 150 degrees Celsius, baking time It is 3 minutes.

Further, the time that development is impregnated in the step 5 is 1 minute.

Further, developer solution from two pentanone of tetramethyl and isopropanol is 3:1 cooperation system with volume ratio in the step 5 At the time for impregnating fixing in the step 7 is 1 minute.

Further, the beginning condition of step 9 plated film is that the chamber pressure of vacuum coating equipment is lower than 3 × 10^-6Torr

Compared with prior art, beneficial effects of the present invention:

1, the present invention realizes that the U-shaped structure structure of circular dichroism is simple, can be by between horizontal body I, horizontal body II and the perpendicular body Simple combination constitute and be similar to three-dimensional spiral structure, to realize strong circular dichroism, structure is simple, and preparation is convenient, is suitble to Large area production preparation.

2, the present invention realizes that the metal material in the U-shaped structure of circular dichroism can also realize circle two instead of gold using copper Color reduces the preparation cost of chiral material.

3, the U-shaped structure of the invention for realizing circular dichroism is chiral micro-nano metal structure, and horizontal body I, horizontal body II are erected with described There is different height difference chiral metal nanostructure between body, can be applied to biological monitoring, enantiomer sensing, polarization conversion and Photoelectronic circuit polarizer.

Detailed description of the invention

Fig. 1 is the schematic diagram for the U-shaped structure that the present invention realizes circular dichroism.

The step of Fig. 2 is the U-shaped structure of the present invention realization circular dichroism that counterclockwise prepared by rotary template substrate is schemed.

Fig. 3 is the circular dichroism spectrum of the embodiment of the present invention 1.

Fig. 4 is the schematic diagram and its preparation step figure for the E type structure that the embodiment of the present invention 4 realizes circular dichroism.

In figure: 1, the first filming orientation；2, the second plated film orientation；3, third plated film orientation；11, horizontal body I；12, horizontal body II； 13, body is erected.

Specific embodiment

The present invention is described in detail combined with specific embodiments below, but not limited to this.