Нанофізика та фізико-хімічне матеріалознавство

Sonosynthesis of Organic Functional Groups on Semiconductor Surface Nanostructured by Cavitation 
R.K. Savkina and A.B. Smirnov
1 V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine. Prospect Nauki, 41, Kyiv-03028, Ukraine. 
E-mail: rada.k.savkina@gmail.com

Multifunctional composite/hybrid materials have already demonstrated good promise in offering solutions in such priority areas as energy harvesting and storage, the environment, human health as well as in material science and nanotechnology. Composites and hybrid systems, being combined from inorganic and/or organic constituents, are currently gaining increasing attention because of intriguing fundamental physics appeared at the nanoscale level. The creation of such materials is now possible with a high degree of complexity due to impressive developments of the technologies. 
One of such promising technology is sonochemistry, which is based on the cavitation phenomenon. The creation of complex structures on the solid surface or in the liquid media involving cavitation phenomenon occurs due to the generation of microjets and shock waves during cavitation bubbles collapse and stipulated by chemical effect of the ultrasound which based on generation of free radicals during cavitation. According to researchers working in the field of fabrication new nanostructured materials, applying the cavitation effects allow accelerating a reaction or permitting use of less aggressive conditions, reducing the number of steps which are required using normal methodology, and open the possibilities for alternative reaction pathways.
In this study, we assess the role of bubble collapse and cavitation on the synthesis of biologically significant organic molecules on сavitation-induced nanostructured semiconductor surface, using Raman and Infra-red spectroscopy methods. It was found that high-intensity (15 W/cm2) and high-frequency (1 ÷ 6 MHz) sonication of Si and GaAs samples in the liquid nitrogen in a focused mode of acoustic action induces changes of the optical, chemical, and structural properties of semiconductor surface. The formation of organic functional groups (C-H and N-H) on semiconductor surface is confirmed by the results of the optical spectroscopy investigations. It is expected that such organic/inorganic hybrid components can be useful as channel in bio-FET devices.