Layer-By-Layer Deposition and Ordering of Low-Molecular-Weight Dye Molecules for Second-Order Nonlinear Optics

Abstract

A combination of electrostatic interactions and covalent bonding is used to form films with low-molecular-weight chromophores by a layer-by-layer deposition process. Using a common, commercially available red dye, this deposition process results in noncentrosymmetric films (see scheme) that exhibit second-harmonic generation (red→green), with χ(2) values as large as 11.3×10−9 esu, that is, six times that of quartz.