Interface effects on the NLO properties of guest-host materials
Résumé
Electro-optical properties of silicon carbide (SiC) nano-sized clusters embedded into three differ-ent polymeric matrices, i.e., poly(methyl methacrylate, poly-N-vinylcarbazole and polycarbonate were investigated. Electric properties of SiC were calculated using time-dependent DFT methods consider-ing an isolated cluster and environmental effects. The concept of the polymeric influence on optical properties of chromophores was executed by the local electric field approach. Electric field created by charge distribution of the surrounding polymer was calculated using guest–host structures obtained by the molecular dynamics simulations. Optical properties of SiC situated in polymeric environments differ from those of free clusters. It is seen more significantly for the hyperpolarizability than for the polarizability. The spatial distribution of SiC in the matrix depends on the kind of polymer and gives an important influence on the obtained local electric field value. The Si–C distances do not change with variation of the polymeric matrix. The geometry of 3C–SiC is very stable and does not change during MD simulations performed at 300 K.