1. Anisotropy and Raman absorption of the polyimide surface irradiated by the ion beam for liquid crystal alignment
- Author
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Son, Phil Kook, Park, Jeung Hun, Jo, Bong Kyun, Lee, Sung Pil, Lee, Joong Ha, Kim, Jae Chang, Yoon, Tae-Hoon, Lee, Taek Joon, and Ree, Moonhor
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LIQUID crystals , *ANISOTROPY , *RAMAN effect , *POLYIMIDES , *ION bombardment , *ELLIPSOMETRY , *ATOMIC force microscopy - Abstract
Abstract: In this paper, polyimide surfaces irradiated by an ion-beam for liquid crystal alignment are investigated by using atomic force microscopy, Raman spectroscopy, and spectroscopic ellipsometry. A liquid crystal cell aligned homogeneously through the ion-beam exposure exhibits electro-optic switching behavior similar to that of a rubbing-aligned liquid crystal cell. However, we found that the surface morphology and bonding molecules of ion-beam-treated polyimide surfaces show properties very different from mechanically-rubbed ones. Experimental results show that optical anisotropy of ion-beam-treated polyimide surfaces results in the formation of hydrogenated amorphous carbon-like structure with a short main-chain, while mechanical rubbing has little effect on structural and compositional variations of polyimide layers. [Copyright &y& Elsevier]
- Published
- 2009
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