Poling self-assembly techniques

Electrostatic layer-by-layer (LBL) self-assembly techniques based on oppositely charged poipelectrolytes can be useful to create stable noncentrosymmetric order in thin films. Using this interesting technique, thermodynamically stable noncentrosymmetric multilayer films can be prepared without any need for poling. Tripathy et al. reported the fabrication stable multilayer films of epoxy-based side chain azo polymers for second-order nonlinear optics.The second-order NLO coefficients of the five-bilayer LBL films of these polymers were found to be comparable to those of spin-coated poled films. A schematic view of the procedure to fabricate polyelectrolyte-based LBL films is shown in Fig. 7. 

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