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45.2: XPS Characterization of Photo‐Alignment Using Adsorbed Dichroic Materials
Author(s) -
Su Linli,
West John L.,
Reznikov Yuri,
Artyushkova Kateryna,
Fulghum Julia E.
Publication year - 2001
Publication title -
sid symposium digest of technical papers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.351
H-Index - 44
eISSN - 2168-0159
pISSN - 0097-966X
DOI - 10.1889/1.1831767
Subject(s) - dichroic glass , x ray photoelectron spectroscopy , adsorption , materials science , substrate (aquarium) , characterization (materials science) , anisotropy , desorption , layer (electronics) , analytical chemistry (journal) , optics , chemistry , optoelectronics , chemical engineering , nanotechnology , organic chemistry , physics , oceanography , engineering , geology
Successful photo‐alignment using adsorbed dichroic dyes can be obtained by properly matching the properties of substrates and adsorbed materials. Our results suggest that photo‐induced anisotropic desorption produces photo‐alignment in such systems. We used various characterization techniques to study the photo‐alignment process. Polarized UV‐vis spectrometry reveals the anisotropy of the alignment layer before and after exposure to linearly polarized UV light (LPUV). X‐ray photoelectron spectroscopy (XPS) shows chemical changes at the surface and interfaces of the substrate materials, adsorbed materials, and liquid crystal. Angle resolved XPS provides information on the distribution of the adsorbed dichroic materials on the substrate surface. The information on the interaction between liquid crystals and alignment layer is crucial to understanding the alignment effect on a molecular level.