Molecular Organic Crystals Dast and Pom in the Form of a Thin Crystalline Film and a Nanocrystal–The New Promising Medium for NLO Application

Abstract

We investigate the process of synthesis of the “red” crystalline form of DAST nanocrystals both by the precipitation and impregnation methods. We developed the impregnation method of the preparation of DAST nanocrystals in a UV-cured matrix based on the specific intermolecular interaction between DAST and polymer molecules in a supersaturated methanol solution. The method allows one to produce a highly concentrated (up to 30%) nanocrystal-filled transparent composition. The nanocomposite is suitable to produce photonics structures by the soft lithography method. The formation of an anisotropic nanocomposite by use of the oriented polymeric matrix is investigated. The second-harmonic generation in very thin (about 1 micron) layers confirms the high nonlinear susceptibility of this material.

Keywords:

• electro-optics
• molecular crystal
• nanocrystals
• non-linear optics

Acknowledgments

The work was made under the support of RFBR Project # 05-02-08048 “Investigation of electro-optic nanostructures with high hyperpolarizability based on the dense packing of nanocrystals in a polymer matrix for the use in microwave optoelectronic elements”; RFBR Project # 06-02-27233, and Project of Russian Federal Agency of Education # 1.3.06 “Investigation of the process of formation of non-linear properties under the transformation from the molecular to nanocrystalline state of organic crystals”.