Photoalignment efficiency enhancement of polyimide alignment layers by alkyl-amine vapor treatment

We have succeeded in enhancing the photoalignment efficiency of polyimide containing azobenzene in the backbone structure by exposing the corresponding precursor (polyamic acid: Azo-PAA) film to alkyl-amine vapor prior to photoalignment. The Azo-PAA film absorbed alky-amines and swelled by 300%. The...

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Bibliographic Details
Published inApplied physics express Vol. 7; no. 8; pp. 81701 - 81704
Main Authors Sakamoto, Kenji, Usami, Kiyoaki, Miki, Kazushi
Format Journal Article
LanguageEnglish
Published The Japan Society of Applied Physics 01.08.2014
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Summary:We have succeeded in enhancing the photoalignment efficiency of polyimide containing azobenzene in the backbone structure by exposing the corresponding precursor (polyamic acid: Azo-PAA) film to alkyl-amine vapor prior to photoalignment. The Azo-PAA film absorbed alky-amines and swelled by 300%. The photoinduced rotation of the Azo-PAA backbone structure occurred more easily in the swollen film. Most of the alkyl-amines in the swollen film desorbed during thermal imidization. As a result of the photoalignment efficiency enhancement, we also succeeded in expanding the controllable pretilt angle range of liquid crystals up to 38° without the appearance of threadlike disclination loops.
ISSN:1882-0778
1882-0786
DOI:10.7567/APEX.7.081701