– 110 – 3 ■ Introduction Along the twentheith century, the information support went from paper to television, and then to multiple kind of display screens. The last technologies allowed to make those screen very thin, and to adapt them to mobile systems. Unfortunatly, the energy capacity of the last battery is not that high, and to preserve them, the screen must be of low energy cost. The luminosity of the screen is then limited. Sun or artificials lights may make the screen difficult to read. To limit this problem, the use of antireflective layers became habitual. In this poster, we will present a new method for a facile fabrication of nanocellular thin films, which gives access to very low refractive index films. ■ Contents of Activity 1. Principle The experimental work consisted in producing a new type of antireflective monolayer coating, based on the use of fluorinated block copolymers. When coated on glass, our fluorinated block copolymers arrange themselves in fluorinated cells in a non fluorinated matrix. Using high pressure CO 2 , it is possible to fill the fluorinated cells to obtain pores of few tenth of nanometers. 2. Antireflective properties To obtain good antireflectives properties, it is necessary to cumulate two differents properties for the film: - The thickness of the film. It must be equal to the quarter wavelenght of the light wavelenght that will be used. Using such a thickness supports the creation of destructive waves and thus lower the reflection. - The refractive index of the film. The ideal refractive index of a single layer antireflective film, in the case of a glass/air interface, would be 1.23. The pores created in our films allowed to lower the refractive index of the film in large proportion, as we could obtain refractive indexes as low as 1.20. 3. Mechanical Properties and Usefulness Mechanically, the nanocellular films are very ductile. They may be used to coat the coming flexible screens that are developped by many companies. Illustration 1: SEM picture of the cell nanostructure of a block copolymer film treated by CO 2 process. (after etching) TX テクノロジー・ショーケースイン・ツクバ　2008 物質・材料 Fabrication of polymer thin films to obtain antireflective layers 代表発表者 DUTRIEZ Cedric ■キーワード : （1） nanocells （2） anti-reflection （3） films 所　　　属 AIST Nanotechnology Research Institute 問合せ先〒 305-8565 つくば市 1-1-5 TEL: 029-861-4432, FAX: 029-861-4432 [email protected]

Fabrication of polymer thin ﬁlms to obtain …...Illustration 1: SEM picture of the cell nanostructure of a block copolymer ﬁlm treated by CO 2 process. (after etching) TX テクノロジー・ショーケース

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Page 1: Fabrication of polymer thin ﬁlms to obtain …...Illustration 1: SEM picture of the cell nanostructure of a block copolymer ﬁlm treated by CO 2 process. (after etching) TX テクノロジー・ショーケース

– 110 – – 111 –

■ IntroductionAlong the twentheith century, the information support

went from paper to television, and then to multiple kind of display screens. The last technologies allowed to make those screen very thin, and to adapt them to mobile systems. Unfortunatly, the energy capacity of the last battery is not that high, and to preserve them, the screen must be of low energy cost. The luminosity of the screen is then limited. Sun or artificials lights may make the screen difficult to read. To limit this problem, the use of antireflective layers became habitual. In this poster, we will present a new method for a facile fabrication of nanocellular thin films, which gives access to very low refractive index films.

■ Contents of Activity1. Principle

The experimental work consisted in producing a new type of antireflective monolayer coating, based on the use of fluorinated block copolymers. When coated on glass, our fluorinated block copolymers arrange themselves in fluorinated cells in a non fluorinated matrix. Using high pressure CO2, it is possible to fill the fluorinated cells to obtain pores of few tenth of nanometers.

2. Antireflective propertiesTo obtain good antireflectives properties, it is

necessary to cumulate two differents properties for the film:

- The thickness of the film. It must be equal to the quarter wavelenght of the light wavelenght that will be used. Using such a thickness supports the creation of destructive waves and thus lower the reflection.

- The refractive index of the film. The ideal refractive index of a single layer antireflective film, in the case of a glass/air interface, would be 1.23. The pores created in our films allowed to lower the refractive index of the film in large proportion, as we could obtain refractive indexes as low as 1.20.

3. Mechanical Properties and UsefulnessMechanically, the nanocellular films are very ductile.

They may be used to coat the coming flexible screens that are developped by many companies.

Illustration 1: SEM picture of the cell nanostructure of a block copolymer film treated by CO2 process. (after etching)

TXテクノロジー・ショーケースイン・ツクバ　2008

物質・材料

Fabrication of polymer thin films to obtain antireflective layers

代表発表者 DUTRIEZ Cedric ■キーワード : （1） nanocells（2） anti-reflection（3） films

所　　　属 AISTNanotechnology Research Institute

問合せ先〒 305-8565　つくば市 1-1-5TEL: 029-861-4432, FAX: [email protected]