Poled sol–gel materials doped with heterocycle-based push–pull chromophores with second-order optical non-linearity

In this work, a previously studied system of a hybrid sol–gel material doped with a push pull chromophore is optimized by co-doping the matrix with carbazole functionalized units, and achieving enhanced second order NLO properties. The microstructure modifications of the hybrid sol–gel matrix have been investigated during the thermal treatment and the poling procedure, together with the stability of the dopants. The thermal treatment performed during the poling process determines the carbazole units degradation while the chromophore molecules remain unaltered and their absorbance features are strongly modified.